Bone Tissue & Axial Skeleton

  1. Skeletal Cartilages
    Contain no blood vessels or nerves

    • Dense connective tissue girdle of perichondrium contains blood vessels for nutrient delivery to cartilage
    • Hyaline
    • Elastic
    • Fibrocartilages
  2. Hyaline Cartilages
    • Provide support, flexibility, and resilience
    • Most abundant type
  3. Elastic Cartilages
    Similar to hyaline cartilages, but contain elastic fibers
  4. Fibrocartilages
    Collagen fibers - have great tensile strength
  5. Appositional
    Cells secrete matrix against the external face of existing cartilage
  6. Interstitial
    Chondrocytes divide and secrete new matrix, expanding cartilage from within
  7. Calcification of cartilage
    • pathologic, but occurs during 
    • Bone growth
    • Old age
  8. Bones of the Skeleton: 2 main groups, by location
    • Axial Skeleton
    • Appendicular Skeleton
  9. Axial skeleton
    skull, vertebral column, thoracic cage
  10. Appendicular skeleton
    upper and lower limbs, shoulder and pelvic girdle
  11. Long bones
    longer than they are wide
  12. Short bones
    • cube-shaped bones (in wrist and ankle)
    • Sesamoid bones (within tendons, e.g., patella)
  13. Flat bones
    thin, flat, slightly curved
  14. Irregular bones
    complicated shapes
  15. Functions of bones
    • support
    • protection
    • movement
    • storage
    • blood cell formation
    • triglyceride (energy) storage
  16. Support
    for the body and soft organs
  17. Protection
    for brain, spinal cord, and vital organs
  18. Movement
    levers for muscle action
  19. Storage
    minerals (calcium and phosphorus) and growth factors
  20. Blood cell formation
    (hematopoiesis) in marrow cavities
  21. Triglyceride (energy) storage
    in bone cavities
  22. Bone Markings: Bulges, depressions, and holes serve as-
    • Sites of attachment for muscles, ligaments, and tendons
    • Joint surfaces
    • Conduits for blood vessels and nerves
  23. Bone Projections to help form joints:
    • Condyle
    • Facet
    • Head
    • Ramus
  24. Bone Projections that are sites of muscle and ligament attachment:
    • Tuberosity
    • Crest
    • Trochanter
    • Line
    • Tubercle
    • Epicondyle
    • Spine
    • Process
  25. Condyle
    large, rounded articular projection
  26. Facet
    smooth, nearly flat articular surface
  27. Head
    bony expansion carried on a narrow neck
  28. Ramus
    arm-like bar
  29. Tuberosity
    rounded projection
  30. Crest
    narrow, prominent ridge
  31. Trochanter
    large, blunt, irregular surface
  32. Line
    narrow ridge of bone
  33. Tubercle
    small rounded projection
  34. Epicondyle
    raised area above a condyle
  35. Spine
    sharp, slender projection
  36. Process
    any bony prominence
  37. Bone markings: Depressions & Openings
    • Meatus
    • Sinus
    • Fossa
    • Groove
    • Fissure
    • Foramen
  38. Meatus
    canal-like passageway
  39. Sinus
    cavity within a bone
  40. Fossa
    shallow, basinlike depression
  41. Groove
  42. Fissure
    narrow, slitlike opening
  43. Foramen
    round or oval opening through a bone
  44. 2 Types of bone tissues:
    • Compact bone
    • Spongy or Cancellous bone
  45. Compact bone
    forms the strong, dense outer layer of bones
  46. Spongy or Cancellous bone
    forms a less strong honeycomb of trabeculae
  47. Structure of a long bone
    • Diaphysis (shaft)
    • Medullary cavity (yellow marrow)
    • Epiphyses
    • Epiphyseal line
    • Articular (hyaline) cartilage
  48. Diaphysis (shaft)
    compact bone collar surrounds medullary (marrow) cavity
  49. Medullary cavity
    • in adults contains fat
    • (yellow marrow)
  50. Epiphyses
    • expanded ends
    • spongy bone interior
  51. Epiphyseal line
    remnant of growth plate
  52. Articular cartilage
    • (hyaline)
    • on joint surfaces
  53. Structure of a long bone Picture
    Image Upload 1
  54. Membranes of Bone
    • Nerve fibers and blood vessels enter the bone via nutrient foramina
    • Secured to underlying bone by Sharpey's fibers
    • Periosteum 
    •     Outer fibrous layer
    •      Inner osteogenic layer
    •           -Osteogenic cells
    •                -Osteoblasts
    •                -Osteoclasts
  55. Osteogenic cells
    stem cells
  56. Osteoblasts
    bone-forming cells
  57. Osteoclasts
    bone-destroying cells
  58. Membranes of Bone: Endosteum
    • Delicate membrane on internal surfaces of bone
    • Also contains osteoblasts and osteoclasts
  59. Image Upload 2
    Bone pic
  60. Periosteum
    covered compact bone on the outside
  61. Endosteum
    covered spongy bone within
  62. Diploe
    spongy bone in flat bones
  63. Bone marrow
    between the trabeculae
  64. Bone PictureImage Upload 3
  65. Hematopoietic tissue
    red marrow
  66. Red marrow cavities of adults: location
    • Trabecular cavities of the heads of the femur and humerus 
    • Trabecular cavities of the diploe of flat bones
  67. Red marrow cavities of infants: location
    medullary cavities and all spaces in spongy bone
  68. Bone tissue 4 cell types:
    Osteogenic (osteoprogenitor) cells - Stem cells in periosteum and endosteum that give rise to osteoblasts

    Osteoblasts - Bone-forming cells

    Osteocytes - Mature bone cells

    • Osteoclasts - Cells
    • that break down (resorb) bone matrix
  69. Haversian system or Osteon
    structural unit
  70. Lamellae
    • weight-bearing
    • column-like matrix tubes
  71. Central (Haversian) canal
    contains blood vessels and nerves
  72. Perforating (volkmann's) canals
    • at right angles to the central canal
    • connects blood vessels and nerves of the periosteum and central canal
  73. Lacunae
    small cavities that contain osteocytes
  74. Canaliculi
    hairlike canals that connect lacunae to each other and the central canal
  75. Trabeculae
    Align along lines of stress

    No osteons

    Contain irregularly arranged lamellae, osteocytes, and canaliculi

    Capillaries in endosteum supply nutrients
  76. Chemical composition of Bone
    only tissue with an organic and inorganic component
  77. Organic
    osteogenic cells, osteoblasts, osteocytes, osteoclasts
  78. Osteoid
    organic bone matrix secreted by osteoblasts
  79. Ground substance
    proteoglycans, glycoproteins
  80. Collagen fibers
    provide tensile strength and flexibility
  81. Inorganic Hydroxyapatites
    • mineral salts
    • 65% of bone by mass
    • mainly calcium phosphate crystals
    • responsible for hardness and resistance to compression
    • trace minerals (fluorine, manganese) add strength
  82. Osteogenesis (ossification)
    bone tissue formation
  83. Bone formation
    begins in the 2nd month of development
  84. Postnatal bone growth
    until early adulthood
  85. Bone remodeling and repair
  86. Intramembranous ossification: Membrane bone
    -develops from fibrous membrane

    Forms flat bones, e.g. clavicles and cranial bones

    Starts with an ossification center inside the membrane

    Osteoblasts secrete bone matrix, which calcifies, and the osteoblasts inside the matrix turn into osteoclasts

    Goes through a stage of woven bone

    Final sandwich structure of inner and outer layer of compact bone with a middle layer of spongy bone develops
  87. Cartilage (endochondral) bone
    • forms by replacing hyaline cartilage
    • forms most of the rest of the skeleton
    • requires breakdown of hyaline cartilage prior to ossification
    • starts with a primary ossification cener in the middle of the diaphysis
    • cartilage in this area calcifies and is replaced by newly formed bone 
    • in the center a cavity forms, which later becomes the medullary cavity
  88. Secondary ossification center
    • develops in the upper and lower epiphysis
    • in the center of it, cartilage is replaced by spongy bone
    • on the outside a strong layer of compact bone develops
  89. Image Upload 4
    bone pic
  90. Interstitial growth
    increased length of long bones
  91. Appositional growth
    increased thickness and remodeling of all bones by osteoblasts and osteoclasts on bone surfaces (periosteum, endosteum)
  92. Epiphyseal plate cartilage 4 functional zones:
    • Proliferation
    • Hypertrophic
    • Calcification
    • Ossification
  93. Proliferation
    • growth zone
    • cartilages cells divide and from stacks or columns of cartilage cells
  94. Hypertrophic zone
    older, stressed cartilage cells enlarge
  95. Calcification aone
    the matrix calcifies and chondrocytes die
  96. Ossification
    • osteogenic zone
    • cartilage is replaced by bone tissue
  97. Up to slide 34 of 5.1 power point
    Study power point slides 35-90
Card Set
Bone Tissue & Axial Skeleton
naming bones in the body